Apparatus for engraving, carving, cutting or chipping metals, wood, stone or the like



July 23, 1968 D. A. @LASER ETAL 3,393,755

APPARATUS FOR ENGRAVING, CARVING, CUTTING OR SHIPPING METALS, WOOD, STONE OR THE LIKE Filed Nov. 14, 19e@ aki-5159.3. L34

'IlIlllllllllllllIllllllllllllllllIl Eby. INVENToRs Dona/d A. /msef' Joh/7 A". f90/mer ATTOR .s

United States Patent O 3,393,755 APPARATUS FOR ENGRAVING, CARVING, CUTTING OR CHIPPING METALS, WOOD, STONE R THE LIKE Donald A. Glaser, 1520 West St., Emporia, Kans. 66801, and John R. Rohner, Sunshine Canyon, Boulder, Colo. 80302 Filed Nov. 14, 1966, Ser. No. 593,988 16 Claims. (Cl. 173-116) The instant invention relates to apparatus for engraving, carving, cutting or chipping metals, wood, stone or the like and, particularly, to pneumatic apparatus for performing precise handworking operations such as the artistic engraving of metal objects.

In the past, years of hard work were required for a person to become an accomplished steel engraver, even if that person started with an inherent artistic ability. Time is the enemy of the American craftsman because our present economy moves at a pace which precludes long apprenticeships. Consequently, the art of steel engraving is in danger of vanishing from the American scene. There is no artistic medium in which a beginner can give so much of himself with so little return and many potential engravers are discouraged from the start.

Steel is highly resistant to engraving, and even the simple line and open curve seem beyond the grasp of the apprentice as engraving tips break and patience abandons the apprentice. Therefore, it is the primary object of the instant invention to provide an engraving apparatus that replaces the chasing hammer and the necessity of applying diicult to master hand pressure with precisely controlled power to the end that apprentice engravers are assisted in the learning of the engraving art and even journeyrnen engravers are aided in that their production rate is increased.

Another -very important object of the instant invention is to provide such an apparatus wherein the power necessary for engraving is supplied pneumatically whereby the engraver need only hand-manipulate the cutting tool without applying force to the same.

Another very important object of the instant invention is to provide a pneumatically operated engraving apparatus wherein the intensity of the force applied to the surface being engraved is variable, whereby the depth of the cut may be closely controlled, and wherein pneumatic forces are intermittently applied to the object being engraved, whereby the cycling rate of the pneumatic hammering mechanism is variable so that the number of cuts per unit time may be closely controlled. The precision and flexibility of such control constitutes one of the principal advantages of the instant invention over more conventional types of pneumatically and electrically operated impact tools, and makes it possible to use the instant invention for delicate tasks such as the working of ivory, silver and other difficult materials, the removal of matrix from small fossil specimens, etc.

A further important object of the instant invention is the provision of such an apparatus having a pneumatically operated hammer mechanism responsive to alternatively applied suction and pressure forces, whereby the hammer mechanism is reciprocable for intermittently applying a controlled force to the surface undergoing engraving without the necessity of manual hammering.

In its broadest aspects, the instant invention provides an engraving apparatus including a hand-manipulable tool wherein a reciprocable hammer is repeatedly caused to collide with a cutting element and force the same against the surface to be engraved. Manifestly, the rate of cycling and the speed of the hammer as the same impacts with the cutting element are controlled by the application of variable pneumatic forces thereon.

3,393,755 Patented July 23, 1968 In the drawing:

FIGURE l is a side elevational view of the engraving apparatus embodying the principles of the instant invention, and including a combination pump and prime mover, a foot pedal, and a hand-manipulable tool interconnected by pneumatic hoses, certain portions of the pneumatic hoses and the work-engaging tip of the hand tool having been broken away for increased clarity;

v FIG. 2 is a right end elevational view of the combination pump and prime mover illustrated in FIG. l;

FIG. 3 is an enlarged view, partially in cross section, taken along line 3-3 of FIG. 1;

FIG. 4 is an enlarged, cross-sectional view taken along line 4-4 of FIG. 1; and

FIG. 5 is an enlarged, cross-sectional view taken along line 5 5 of FIG. 1.

Engraving apparatus embodying the principles of the instant invention is broadly designated by the numeral 10 and illustrated in FIG. l. Apparatus 10 includes pneumatic hammer mechanism in the nature of a handmanipulable instrument 12, a combination pump and prime mover assembly 14 to provide pressure and suction for instrument 12, and means for selectively varying the intensity of the suction from assembly 14 in the nature of a foot pedal 16. Assembly 14 includes prime mover means in the nature of an electric motor 18 and a pneumatic pump 20. Motor 18 has a shaft 22 interconnected with pump 20 at the left-hand end of assembly 14 and extending externally at the right-hand end of assembly 14. Pump 20 has an inlet conduit 24 providing a suction source when motor 18 operates to actuate pump 20, and a discharge line 26 providing a pressure source upon actuation of the pump 20.

Instrument 12 includes a hollow body 28 having a scribe member 30 at one end thereof, member 30 including a tool element 32 having its remote end (not shown) adapted to engage and mark a surface being engraved. Body 28 presents a chamber `34 and a piston element 36 is reciprocably mounted within chamber 34 as can be seen viewing FIG. 3. A series of vent holes 38 extend radially through body 28 communicating the left-hand end 34a of chamber 34 with the surrounding atmosphere. A portion 30a of member 30 is received within instrument 12 and is maintained therein by a pin 40. Structure for imparting a constant yieldable bias on element 36 toward member 30, in the nature of a coil spring 42, is mounted within chamber 34 as can be seen viewing FIG. 3. A coupling 44 is carried by the righ-hand end of instrument 12 providing a conduit 46 communicating chamber 34 with a hose 48.

Suction conduit 24 communicates with a suction manifold 50 and a conduit in the nature of a hose 52 communicates manifold 50 with foot pedal 16. Pedal 16 includes a base 54 and a control component in the nature of a foot lever 56 hingedly mounted on base 54 by a hinge pin 58. A spring (not shown) biases lever 56 relative to base 54 around hinge pin 58 in a counterclockwise direction viewing FIG. l, and into the solid line position illustrated in FIG. 5.

Lever 56 has an apertured plate 60 depending therefrom and an aperture 62 in plate 60 is located to coincide with the opening 64 in a nipple 66 communicating with hose 52 `as can be seen viewing FIG. 5. A coil spring 68 biases nipple 66 toward plate 60, and nipple 66 is maintained in slidable engagement with the surf-ace of plate 60 by the cooperation of anges 66a with surface 60a of plate 60. It can be seen, viewing FIG. 5, that when lever 56 is in its extreme position illustrated in solid lines, aperture 62 and opening 64 are aligned, and suction conduit 24, along with manifold 50 and hose 52, is in fluid cornmunication with the environmental conditions surrounding foot pedal 16 providing a source of higher pressure fluid for conduit 24 and it can be seen viewing FIG. 1, that during operation of apparatus 10, air will be drawn through hose 52 in the direction indicated by -arrow 70. Manifestly, upon shifting of plate 60 in a downward `direction and into the ydotted line position illustrated in FIG. 5, aperture 62 will be shifted out of alignment with opening 64, thus decreasing the amount of surrounding air or higher pressure fluid available to conduit 24 and manifold 50. Thus, the absolute pressure in conduit 24 and manifold 50 -will decrease as pump 20 strives to pull more fluid through hose 52 upon shifting of apertured plate 60 in a downward direction.

Valve means in the nature of a rotary valve 72 is provided for alternately coupling hose 48 with manifold 50 and pump discharge line 26. Valve 72 has a suction connector 74 coupled with manifold 50 through tube 76. A pressure inlet fitting 78 on valve 72 is coupled with line 26 through pipe 80. An oil filter 82 and a pressure relief valve 84 are mounted on pipe 80. Valve 72 also includes a coupler 86 mounting hose 48 on valve 72 and providing an opening 88 in fluid communication with chamber 34 in instrument 12.

Valve 72 includes a hollow housing 90 rotatably receiving an elongated rotor 92 therein. Rotor 92 is spaced from connector 74 presenting a chamber 94 communicating with manifold 50 through connector 74 and tube 76. Rotor 92 has a circumferential groove 96 therearound in continuous communication with pump discharge line 26 through fitting 78 and pipe 80. A -port in the nature of an elongated channel 98 extends axially of rotor 92 and is in continuous communication with chamber 94 during rotation of rotor 92.

Channel 98 has an axial extending portion 98a and a radially extending portion 98b, and it can be seen viewing FIG. 4, that during the rotation of rotor 92, portion 98b intermittently communicates opening 88 with chainber 94 and thus with suction manifold 50. A port 100 shown in dotted lines in FIG. 4 is disposed on the opposite side o'f rotor 92 from channel 98. Port 100 is similar in configuration to channel 98 and provides intermittent communication of opening 88 with pressure source 26 alternately with the communication of opening 88 with suction source 24. Thus, upon rotation of rotor 92, chamber 34 is alternately placed in fluid communication with the pressure source and the suction source of pump 20.

Valve 72 is provided with mechanism 102 for coupling valve 72 with the 4right-hand end of shaft 22 for rotation therewith. Mechanism 102 includes a sheave 104 rotatable with rotor 92 and a pulley 106 rotatable lwith shaft 22 as can be seen viewing FIG. 2. A belt 108 is trained around sheave 104 and pulley 106, the llatter having an axially shiftable side portion 110 in a fixed side portion 112. Portions 110 and 112 have inclined inner surfaces which diverge radially outwardly, and portion 110 is yieldably biased toward portion 112 by a coil spring 1114 as can be seen viewing FIG. l. Means for varying the speed of rotor 92 in the nature of a lever mounted idler 116 is mounted adjacent belt 108. Idler 116 is rotatably mounted on a lever arm 118, the latter being swingably mounted for movement about pivot pin 120. It can be seen that upon swinging of arm 118 in a counterclockwise direction about pin 120 in FIG. 2, belt 108 is tightened on pulley 106 and portion 110 is forced away from portion 112. Thus, belt 108 moves toward shaft 22 thereby decreasing the linear speed of belt 108 and thus, the rotative speed of rotor 92.

In operation, spring 42 continuously urges piston element 36 toward member 30. Upon energization of motor 18, pump operates to create a vacuum in manifold 50 and an elevated pressure in discharge line 26. Likewise, pipe 80 will be pressurized and tube 76 will be evacuated. As rotor 92 rotates, hose 48 will alternately be pressurized and evacuated as port 100 and channel 98 alternately and intermittently communicate with the latter. Thus, chamber 34 will be alternately pressurized and evacuated. When apertured plate 60 is in the position indicated by the solid lines in FIG. 5, manifold will be in communication with the surrounding atmosphere and, therefore, the absolute pressure in manifold 50` will be only slightly below atmospheric pressure. With plate in that position, the intensity of the suction in manifold 50 will be insufficient to `withdraw element 36 from contact with member 30 against the bias of spring 42. As foot lever 56 and thus plate 60 are incrementally moved toward the dashed line position indicated in FIG. 5, aperture 62 will move incrementally out of alignment with opening 64 and the absolute pressure in manifold 50 will incrementally drop as the open inlet area of opening 64 decreases. Manifestly, t-he lower the absolute pressure (or suction) in manifold 50, the farther element 36 will be withdrawn from member 30 each time channel 98 communicates with chamber 34.

Upon further rotation of rotor 92, as can be seen viewing FIG. 4, after element 36 is withdrawn by the evacuation of chamber 34, port will be moved into communication with chamber 34 and the latter will be pressurized to force element 36 rapidly toward member '30 and impacted thereagainst. Spring 42 assists the pressure in chamber 34 in moving element 36 toward member 30 to increase the momentum of element 36, thereby increasing the intensity of the impact when element 36 collides with member 30. The impactive force of element 36 on member 30 is transmitted through the latter to the operative end of tool 32 creating a substantial driving force causing the operative end of tool 32 to dig into the surface being engraved.

Further, depending upon the artistic nature of the figure to be engraved, tool 32 is preferably variable in stroke frequency. By moving arm 118 in a counterclockwise direction viewing FIG. 2, the number of strokes per minute is relatively decreased. Conversely, by moving arm 118 in a clockwise direction, the number of strokes per minute of tool 32 against the surface being engraved, is relatively increased.

Apparatus 10 provides a pneumatically operated, handmanipulable engraving mechanism having extreme tlexibility and utility heretofore unknown in the engraving field. By the simple expedient of shifting arm 118, the frequency of the stroke may be set as desired for the required job. Depression of foot lever 56 increases the intensity of the suction available at manifold 50 to thereby increase the power available at the operative end of tool 32. The action of spring 42 and the pressure from line 26 are duplicative in that both operate to move piston 36 toward member 30. Either the action of the spring or the pressure would cause piston 36 to move toward member 30 and impact with the latter. However, in the preferred embodiment illustrated in the drawing, the action of spring 42 and the pressure from line 26 are applied simultaneously to piston 36 to increase the 'momentum of the latter during its movement toward member 30. Through the use of apparatus 10, it is apparent that an apprentice engraver would be greatly assisted in that he would not have to hold an engraving tool in the proper position while striking the same with a hammer with the proper amount of force. Additionally, apparatus 10 may be used by a journeyman engrave'r so that his rate of production is substantially increased. Hence, all of the aims, objects and purposes of the instant invention have been fulfilled in a substantial sense.

Having disclosed an illustrative embodiment of the invention, it is to be understood that various modifications thereof would be used without departing from the spirit of this invention. Accordingly, it is intended that the invention should be deemed limited only by the scope of the appended claims and their equivalents.

Having thus described the invention, what is claimed as new and desired to he secured by letters Patent is:

l. In apparatus for performing precise hantlworking operations such as the artistic engraving of metal objects,

a hand-manipulable instrument, including a hollow body having an elongated chamber therein and an impact-receiving member at one extremity of the chamber, an impact-imparting piston shiftably contained in the chamber and adapted to move into and out of impacting engagement with the member, and a workengaging tool element mounted on the member externally of the body;

means for moving the piston toward the member;

a source of fluid medium suction; and

valve means for intermittently coupling said source with said chamber to move the piston away from the member.

2. The invention of claim 1, wherein is included means for selectively varying the intensity of the suction available from said source.

3. The invention of claim 2, wherein said selectively variable means includes a control component variably communicating said source with a supply of higher pressure fluid whereby the intensity of said suction is selectively raised and lowered.

4. The invention of claim 3, wherein said control component includes a conduit normally communicating said source with atmospheric conditions and a foot pedal including a shiftable, apertured plate for selectively and variably blocking and unblocking said conduit.

5. The invention of claim 1, wherein said valve means includes a valve having a suction inlet communicating with said source, an opening communicating with said chamber and a rotatable rotor having a port therein for intermittently coupling said inlet and `said opening as the rotor is rotated.

6. The invention of claim 5, wherein said rotor is elongated and rotatable about its longitudinal axis, said port including an elongated channel having an axially extending portion and a radially extending portion.

7. The invention of claim 1, wherein is included a source of uid medium pressure, said valve means alternately coupling said pressure lsource and said suction source with the chamber whereby said pressure source and said suction source alternately urge the piston toward and away from the member.

8. The invention of claim 7, wherein said valve means includes a valve having a suction inlet communicating with said suction source, a pressure inlet communicating with said pressure source, an opening communicating with said chamber and a rotatable rotor having a pair of ports therein, one of said ports intermittently coupling said suction source and said opening as the rotor rotates while the other port intermittently and alternately couples said opening and the pressure source.

9. The invention of claim 8, said suction source and said pressure source being the suction and discharge respectively of a fluid pump.

10. The invention of claim 9, wherein is included prime mover means for said pump and mechanism coupling said prime mover and said rotor for rotation of the latter upon actuation ofthe prime mover.

11. The invention of claim 8, wherein is included means for varying the speed of rotation of said rotor.

12. The invention of claim 1, said means for moving the piston toward the member including structure for imparting a continuous yieldable bias on the piston toward the member.

13. In an air-operated engraving apparatus,

pneumatic hammer mechanism having a piston element therein reciprocable in response to alternative pressurization and evacuation of said mechanism;

a member on said mechanism adjacent one extremity of the path of travel of said element, said element being located for striking said member during movement toward said extremity as the element reciprocates, said member having tool means thereon external of said mechanism adapted for inscribing a surface to be engraved when the member is struck by said element;

a source of fluid medium suction;

a source of Huid medium pressure; and

valve means coupled with said mechanism and said sources for communicating said mechanism alternately with each source respectively to correspondingly pressurize and evacuate the mechanism whereby said member is repetitively struck by said element.

14. The invention of claim 13, wherein is included means for yieldably urging the piston element toward said member.

15. The invention of claim 13, wherein the communication of said suction source with said mechanism is operative to move said piston away from said member.

16. The invention of claim 15, wherein is included means for selectively varying the intensity of the suction available from said suction source.

References Cited UNITED STATES PATENTS 399,789 3/ 1889 Scott 173--116 2,168,806 8/1939 Reilly 173-116 2,676,464 4/1954 Warren 173-116 JAMES A. LEPPINK, Primary Examiner. 

1. IN APPARATUS FOR PERFORMING PRECISE HANDWORKING OPERATIONS SUCH AS THE ARTISTIC ENGRAVING OF METAL OBJECTS, A HAND-MANIPULABLE INSTRUMENT, INCLUDING A HOLLOW BODY HAVING AN ELONGATED CHAMBER THEREIN AND AN IMPACT-RECEIVING MEMBER AT ONE EXTREMITY OF THE CHAMBER, AN IMPACT-IMPARTING PISTON SHIFTABLY CONTAINED IN THE CHAMBER AND ADAPTED TO MOVE INTO AND OUT OF IMPACTING ENGAGEMENT WITH THE MEMBER, AND A WORKENGAGING TOOL ELEMENT MOUNTED ON THE MEMBER EXTERNALLY OF THE BODY; MEANS FOR MOVING THE PISTON TOWARD THE MEMBER; A SOURCE OF FLUID MEDIUM SUCTION; AND VALVE MEANS FOR INTERMITTENTLY COUPLING SAID SOURCE WITH SAID CHAMBER TO MOVE THE PISTON AWAY FROM THE MEMBER. 